Recirculating baths are used in laboratory settings for providing a controlled temperature working liquid, such as water, in a reservoir. The end user may utilize the recirculating bath by placing their application in the reservoir or by recirculating the working liquid between the reservoir and an external application. Conventional recirculating bath applications include placing beakers or other containers in the bath reservoir, or work area, and controlling the temperature of an external jacketed vessel. To control the temperature of the working liquid, the recirculating bath moves the liquid past heating or cooling elements located in the bath reservoir so as to achieve a uniform desired temperature.
Conventional recirculating baths include a base unit and a head unit. The base unit includes the reservoir and a cooling unit having a cooling element located in the reservoir. The cooling element enables the cooling unit to remove heat from the working liquid. A work area cover, or lid, may be provided on top of the base unit that provides access to the work area of the reservoir. Conventional head units include an immersion pump for recirculating the working liquid, and an immersion heater for providing heat to the working liquid. The head unit also includes a human machine interface (HMI) that allows the user to program the head unit to maintain the working liquid at a desired temperature, and to otherwise operate the recirculating bath.
In operation, the head unit sits on top of the base unit so that the immersion heater and immersion pump project downward into the reservoir through an opening in the top of the base unit. This orientation locates the heating element of the immersion heater and the immersion pump in the working liquid. The head unit may thereby control the temperature of and circulate the working liquid. The HMI of the head unit projects upward from the base unit to provide access to the user and enable the user to control operation of the recirculating bath.
Conventional head units take up space on the top of the base unit and restrict access to the reservoir. The immersion pump, immersion heater, and cooling elements also occupy space in the bath reservoir, thereby restricting the size and utility of the reservoir work area. The heating and cooling elements may also over-heat or over-cool samples that inadvertently come into contact with the elements, are difficult to keep clean, and can cross-contaminate working liquids in different base units or between different lab applications.
Thus, there is a need for improved recirculating baths that have increased utility and reduced maintenance.